Fujii K, Sadoshima S, Okada Y, Yao H, Kuwabara Y, Ichiya Y, Fujishima M
Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka City, Japan.
Stroke. 1990 Feb;21(2):283-90. doi: 10.1161/01.str.21.2.283.
We used positron emission tomography to examine retrospectively the effects of blood pressure on regional cerebral blood flow and oxygen metabolism in seven normotensive and eight hypertensive patients with a history of transient neurologic deficits. In the hypertensive patients, a decrease in regional cerebral blood flow was closely related to blood pressure; these changes were most pronounced in the supratentorial structures, especially the striatum and thalamus. In contrast, the regional cerebral metabolic rate for oxygen was less related to blood pressure. Consequently, the regional oxygen extraction fraction was increased in the hypertensive patients, while regional cerebral blood volume and the regional cerebral blood flow volume ratio were unchanged. Multivariate regression analysis confirmed that hypertension was an independent factor affecting regional cerebral blood flow. The analysis also disclosed that age, sex, hematocrit, smoking, and PaCO2 affected regional cerebral blood flow. These findings suggest that the hemodynamic reserve in hypertensive individuals is reduced, which may predispose them to cerebral ischemia and perhaps stroke, even during small decreases in cerebral perfusion pressure.
我们采用正电子发射断层扫描技术，对7名血压正常和8名有短暂神经功能缺损病史的高血压患者的血压对局部脑血流量和氧代谢的影响进行了回顾性研究。在高血压患者中，局部脑血流量的减少与血压密切相关；这些变化在幕上结构中最为明显，尤其是纹状体和丘脑。相比之下，局部脑氧代谢率与血压的相关性较小。因此，高血压患者的局部氧摄取分数增加，而局部脑血容量和局部脑血流量体积比未发生变化。多变量回归分析证实，高血压是影响局部脑血流量的独立因素。该分析还表明，年龄、性别、血细胞比容、吸烟和动脉血二氧化碳分压会影响局部脑血流量。这些发现表明，高血压个体的血流动力学储备降低，这可能使他们即使在脑灌注压稍有下降时也易发生脑缺血甚至中风。
